1. Field of the Invention
This invention pertains generally to supports, and more specifically to stands, brackets and bases for supports. In a most preferred manifestation of the invention, the invention pertains to microphone stands.
2. Description of the Related Art
Boom stands, which will be understood herein as vertically rising stands having at least one arm capable of extension in a horizontal direction, are used to support many diverse items. Lights, microphones, cameras, and many other electrical and non-electrical items too numerous to individually list herein are supported thereon. Most commonly, the item to be supported will preferably be easily relocated, as will the stand or at least the boom. This ability to provide relatively adjustable and easily relocated support is in great demand. Frequently, a plurality of these boom stands will be required, such as, for exemplary purposes but not limited thereto, in the case of a musical or theatrical performance where different performers or different parts of a stage are preferred to be either illuminated or coupled into an audio system.
Depending upon the particular item to be supported, the boom stand may have several requirements which must be met to perform satisfactorily. Among these, one common requirement is the ability to readily and rapidly reposition the boom, and then subsequent to the repositioning, anchor the boom into a new fixed position. This ability to readily and rapidly reposition the boom permits the stand to be placed at a convenient location along the ground or floor, without great care in the precise positioning. Once the base is located, then the boom arm may be moved into proper alignment. When any of the moving joints or connections are adjusted into new position, it is most desirable for the positions to be arrived at smoothly, and then locked into place without significant change of position during the locking procedure.
Since the boom may extend some distance from the base, it is generally desirable to incorporate significant mass into the base, to provide some measure of stability during movement or adjustment of the boom and subsequent thereto to best maintain the location of the boom. Unfortunately, in the prior art this often led to the use of a large and very massive base, typically of disc, slightly domed, or similar shape. Such a base is not readily transported, nor can it be used or stored in close arrangement with other bases. Consequently, it is not possible to tightly and compactly arrange, use or store a plurality of similar stands.
To provide more compact storage and lighter weights, a number of designers have resorted to tripod stands. These stands are extremely undesirable for several different reasons. First and foremost, the tripod legs, to avoid the need for substantial mass, must be relatively long. Long legs in turn form a serious hazard for anyone passing near to the boom stand. In the event a boom stand is accidentally knocked over, the item supported thereon may be destroyed. In the case of the performing arts, the microphones that are supported thereon may cost thousands of dollars to replace. Furthermore, the disruption to a performance when a stand is accidentally toppled is highly undesirable.
While the application for the boom stand will to some degree potentially affect the various dimensions and some of the configurations not only of the base, but of the stand as well, including such things as particular lengths or dimensions of the base and the boom, most desirably a boom stand will offer substantial flexibility in both application and physical arrangement and positioning. This flexibility is a desirable part of the benefits of such a stand, which is in part what separates such a stand from a fixture or anchored support.
One of the major factors which controls the applications for which the stand may be used is the coupling between boom and stand. Heretofore in the prior art, one such connection was made as a simple solid connection by thumbscrew or the like to pull two flat surfaces together. This type of connection had almost no resistance to pivotal forces, since the measure of forces upon an arm are calculated by not only the force applied, but also by the distance from the point of rotation. Consequently, when even a small force is applied at a great distance such as at or near the end of a boom arm, the force is magnified by the multiple of relative distance from pivot. Said another way, a first force applied at ten times the distance from a pivot as a second point would require ten times the first force to be applied in an opposite direction at the second point to cancel the first force. In the case of a small knuckle serving as the pivot, this knuckle may be hundreds or even thousands of times closer to the pivot than the end of the boom, and consequently require hundreds or thousands of times the force to prevent rotation about the pivotal axis. As is known in the industry, all too often even minor forces of only a few pounds at the end of the boom overcome the resistance at the knuckle, since these few pounds require thousands of pounds of force to stop such rotation. As a result, the few pounds of force cause the boom to realign undesirably, and therefore require all too frequent re-alignment.
Several different approaches have been attempted to overcome the inherent limitations of these small knuckles or flexible joints. One such approach is illustrated in U.S. Pat. No. 4,671,478 by Schoenig et al, the contents which are incorporated herein by reference. As illustrated therein, the knuckle may comprise two discs designed to mate together at surfaces that are rippled in a complementary radial pattern about the pivot point. As long as both surfaces have complementary geometries, then the engagement of the ridges on one surface occur within the valleys of the opposing surface. To rotate the joint, one must first loosen a bolt passing through the pivot point, to allow the two surfaces to climb up ridge to ridge before passing into the next complementary ridge-valley spacing. When the most desirable ridge-to-valley position is located, then the bolt passing through the pivotal axis may be tightened to prevent any further movement. Since any rotation would require a spreading of the two surfaces, this type of connection frequently has substantial strength and rigidity, so long as the bolt through the pivotal axis is kept secure. Unfortunately, and owing to the discontinuous nature of the engaging surfaces, movement of such a pivotal joint is precarious. Said another way, when the bolt holding the two surfaces tightly in engagement is loosened just beyond the point required to permit ridge-peak to ridge-peak contact between the two surfaces, then all resistance is suddenly and instantaneously lost, and the boom is entirely free to move and drop. So, in order to obtain rotary movement, there is no ability to gradually reduce the frictional forces, but instead the movement occurs instantaneously and sometimes without warning. A number of additional patents illustrate the various techniques that have been tried with these relatively small knuckles, including Lewis in U.S. Pat. No. 2,532,173; Hoshino in U.S. Pat. No. 5,146,808; Arledge in U.S. Pat. No. 5,757,943; and Dunbar in 2002/0066837, the contents of each which are incorporated herein by reference.
Other artisans have proposed addressing the force amplification or leveraging by providing an anchoring or locking arrangement which circumscribes the pivotal axis, but which is displaced therefrom by some radial distance. Exemplary of such an arrangement is Masterson in U.S. Pat. No. 2,527,436, the contents which are incorporated herein by reference. While this arrangement requires somewhat more space than the knuckle would, the relative distances between pivot and boom end versus pivot and locking point are substantially reduced, and then the amount of force and also the amount of ingenuity required to operate the device tend to be better kept in check. Nevertheless, these arrangements still place significant forces upon a small thumbscrew or the like, and such arrangement will invariably fail when relatively meager forces are applied at the ends of the boom. Additional patents which illustrate this type of mount include Schaafin U.S. Pat. No. 1,517,251; Gelb in U.S. Pat. No. 1,611,903; Wright in U.S. Pat. No. 2,129,898; Diesbach in U.S. Pat. No. 2,278,250; Curtis in U.S. Pat. No. 2,299,683; Wright in U.S. Pat. No. 2,366,950; Blair in U.S. Pat. No. 2,481,717; Gebhardt in U.S. Pat. No. 4,773,621; Wu in U.S. Pat. No. 6,332,621; and Chen in U.S. Pat. No. 6,481,913, the contents of each which are incorporated herein by reference. With each of these designs, any vibrations that are induced in the shaft will be directly transferred through to the boom and ultimately to the device. Where sensitive electrical or electronic devices are placed upon these mounts, including such devices as microphones, lights, cameras or the like, this transmission of vibration is clearly undesirable.